Medical images obtained using digital radiology can be easily stored, transferred, and analyzed. And while it was thought initially that digital imaging would bring an end to low-quality images (which may be rejected and/or repeated), this is not the case. Some studies have put the rate of rejected images at many radiology departments above 10%, reaching even 15% in some cases.
In radiology, an image that is evaluated and deemed to have poor quality is rejected. An image that is taken more than once is considered repeated (whether it was rejected, or simply repeated without being labeled rejected). The ease of acquisition in digital radiology, especially with cassette-less systems where no manual intervention occurs between receptor exposure and image readout, has made it easy to repeat imaging, possibly without an appropriate evaluation and rejection. On many systems, radiographers can simply delete unwanted images, which are ultimately never accounted for. Thus, in some systems, the fact that images are simply repeated and not rejected may go unaccounted for. Additionally, many rejected images often simply reside in the system until they are removed to free space for more images. This makes keeping track of the extent of repeated images with many existing systems difficult.
Subjecting patients to repeated imaging is both dangerous (due to the additional exposure to radiation) and wasteful. Thus, there is a need for a way to keep track of the extent of repeated imaging at medical facilities in order to identify cases where the extent of repeated imaging is not within the norm.